Search results for "Calipers"
showing 4 items of 24 documents
Ex vivo measurement reliability using two different cbct scanners for orthodontic purposes
2012
Background There are many cone beam computed tomography (CBCT) scanners available on the market: detector technology, algorithm precision, and scanner settings influence image quality. The aim of this study was to compare the accuracy of linear measurements made on images of the same sample obtained using two different CBCT scanners. Methods Twenty-eight linear measurements between orthodontic anatomical landmarks that were marked with gutta-percha points on a fresh sacrificed lamb head were taken three times. The head was scanned with two CBCT scanners using different scanning parameters. Digital Imaging and Communications in Medicine (DICOM) images were reconstructed and the same measurem…
Using the Breeder genetic algorithm to optimize a multiple regression analysis model used in prediction of the mesiodistal width of unerupted teeth
2014
For the prediction of the unerupted canine and premolars mesiodistal size, have been proposed different variants of multiple linear regression equations (MLRE). These are based on the amount of the upper and lower permanent incisors with a tooth of the lateral support. Aim of present study was to develop a method for optimization of MLRE, using a genetic algorithm for determining a set of coefficients that minimizes the prediction error for the sum of permanent premolars and canines dimensions from a group of young people in an area Romania's central city represented by Sibiu. To test the proposed method, we used a multiple linear regression equation derived from the estimation method propo…
Spiral-CT und 3 D-Rekonstruktion des Tracheobronchialbaumes zur Auswahl geeigneter Doppellumentuben vor Einzellungenbeatmung
1997
Purpose To assess the potential of 3-D spiral CT in the selection of adequate double-lumen tubes (DLT) for one-lung-ventilation. Materials and methods 3-D spiral CT of eight different DLTs was performed with standardized acquisition parameters: section thickness 4 mm, table speed 6 mm/s, increment 3 mm and standardised thresholds, window settings and magnification zoom. The accuracy was confirmed by measuring 3-D objects on screen and original DLTs by vernier caliper. 3-D spiral CT was performed in 20 patients preoperatively with slice thickness 4-8 mm, pitch 1-1.5, increment 4-8 mm. To select the adequate DLT size the 3-D reconstructions of the patient's tracheobronchial tree and of the DL…
Accuracy of automatic airway morphometry in computed tomography-correlation of radiological-pathological findings.
2010
Abstract Objectives Airway morphology shows characteristic changes in different pathologies. This study assesses the accuracy of a current automatic airway assessment technique by correlating CT images of porcine airways to histological slices of the same localization. Materials and methods Four isolated and ventilated porcine lungs were frozen in a liquid nitrogen bath and examined with a CT scanner (MDCT). This technique both preserved normal radiomorphological appearance and made it possible to slice the specimens for histological examination for subsequent correlation. The parameters wall thickness (WT), wall percentage (WP), and total diameter (TD) were assessed by computer-aided measu…